The present invention relates to an apparatus for the automatic selecting out of milk during machine milking comprising a measuring apparatus for the control of the quality of the supplied milk a distributing valve mechanism with a milk input and several milk outputs, as well as a seal mechanism for the optional dosing of the milk outputs and for the optional guiding of the stream of milk into one of several lines, and a control device that actuates the distributing valve mechanism for selecting out milk,
As is known, during machine milking milk from a large number of animals ends up in a collection tank. Thereby, the yielded milk quality can be heavily spoiled by the milk of diseased animals, especially those with a just beginning and not yet diagnosed illness. To insure a high milk quality it is therefore requisite to carry out a monitoring of the milk during the milking process and, at the recognition of milk of unacceptable quality, to select out the milk before it ends up in the collection tank.
In particular, raw milk may not, in accordance with xc2xa73 of the milk ordinance, show any xe2x80x9cabnormal sensory characteristics.xe2x80x9d Assessing of the quality of the milk for changes during the automatic milking process is already possible in known apparatuses. Apparatuses of the kind described in the introduction are known that make use of the fact that the ion content in the milk of ill animals differs from that in the milk of healthy animals. In this way, the conductivity of the milk serves as a parameter by which a selecting out of the milk of insufficient quality can be carried out.
An apparatus of this type is disclosed in DE 196 30 146. In the milking apparatus described therein, a measurement chamber including a sensor element for the detection of the conductivity and temperature of the milk is disposed in the valve housing, wherein the measurement chamber is in fluid communication with the housing interior by at least one opening. This arrangement allows, in particular, a dependable recognition of mastitis diseases in the milked cows. To fulfill the legal requirements. It would be desirable to be able to recognize even more sources of registerable changes in the milk and to correspondingly control a selecting out of the milk.
It is therefore the object of the present invention to provide a new apparatus and a new method for the automatic selecting out of milk of the type mentioned in the introduction that, in comparison to traditional apparatuses and methods of this type, more reliably meet the requirements for milk dictated by quality concerns, especially the monitoring of the abnormal sensory characteristics.
This object is solved in an inventive manner with an apparatus like that described in the introduction for the automatic selecting out of milk, wherein the measuring system comprises a detection means for the automatic detection of particles in the milk stream.
Through the particle detection, it is possible to determine if there are particles present in the milk stream that either have formed due to changes caused by infection or that have gotten into the milk stream due to the contamination of the udder or milking machine. The particles of the first type are, in particular, suppurating particles that can appear with a size from 0.5 to 3 mm. Especially in the case of illnesses which result in a formation of pus in the area of the udder, pus particles occur in the milk that, in accordance with the present invention, will now also be detectable during machine milking.
In a preferred embodiment the detection means comprises a signal transmitter for the transmitting of signals and a signal receiver for the receiving of signals. The transmission of appropriate signals, which are affected in differing ways by the milk and by the particles contained therein, allows a detection of particles that can be substantially carried out without disturbing the milk flow. To this end, advantageously an optical signal transmitter and receiver as well as a transmitter and receiver operating in the range of microwaves are may be used.
In a further advantageous embodiment of the present invention, the detection means comprises an electronic analyzing circuit that receives data from the signal receiver. The analyzing circuit is thereby preferably provided as a microcontroller that can exchange data with the signal transmitter and receiver via, for example, electrical wires or also over a wireless connection. When the signal transmitter and receiver are provided as current and voltage sources or as sensors, these can also be integrated into the microcontroller. For the analyzing circuit, therefore, a very compact, interference-free and robust structure may be realized.
In a preferred embodiment the detection means comprises an area-like flat filter element for the filtering out of particles from the milk stream. This filter element extracts particles exceeding a predefined size from the milk stream, whereby these are then, independent of the milk stream, accessible for measurement.
In a further advantageous embodiment, the detection means comprises an apparatus for the cleaning of the filter element. It is thereby possible to carry out quantitative measurements during the entire milking process, since constant measurement conditions can be maintained on the filter element during the entire milking process in which the particles are continuously removed from the filter element in this way, it is possible to correspondingly select out milk during the different stages of the milking process in which the quality of the milk can vary entirely.
In yet another preferable form of this embodiment, the filter element is rotated around an axis. In particular when the filter element is, for example, provided as a grid or as a filter with only longitudinal elements, it is effective to rotate the filter element in order to carry out a washing of the particles from the grid surface by means of the milk stream. Thereby, the filter element can be so positioned such that particles that are caught on one surface of the grid are flowed against from behind, while the particle free surface of the grid selects out particles from the milk stream. A nearly parallel flow of the milk stream with respect to the grid surface is possible as well.
Preferably the detection means comprises an actuation element for the rotation of the filter element. The cleaning of the filter element can be carried out therewith prior to each measurement process, independent of the degree of contamination, whereby the microcontroller takes over the driving of the actuation element as is appropriate.
In a further preferred embodiment, the filter element comprises electrically conductive elements that are arranged at a distance and isolated from one another. When current or voltage is introduced into this element, the amount of particles present on the filter surface can be detected in an easy manner, since changes occur in the relationships between the resistances in the filter element as a consequence of the deposited particles.
Advantageously, the conductivity of the elements is dependent on the length of the elements. It is thereby possible to receive information about the particle sizes.
In a further preferred embodiment, the filter element comprises an area in which the conductive elements each have a first distance from one another and a further area in which the conductive elements each have a second distance from one another. Thereby, it is possible to select particles according to size in order to, for example, extract information about the type of illness of the animal.
In a further advantageous embodiment of the intention in which a filter element is provided, the detection means comprises a radiation source for the transmitting of electromagnetic radiation in the direction of the filter element and a radiation sensitive sensor element for the receiving of the transmitted radiation from the direction of the filter element. With this arrangement, the structure of the filter element is kept simple, as no electrical feed lines are necessary. The radiation source and the radiation sensitive sensor element are thereby so arranged so that the radiation sensitive sensor element receives the radiation once an interaction with a surface of the filter element has taken place.
In particular, the particle detection is attained by measuring the loss of intensity during the passing of radiation through the filter element, i.e., during the transmission. Preferably, the filter element will be rotated to a suitable position for this measurement, for example, when the filter element is in any case brought into the xe2x80x9ccleaning positionxe2x80x9d, wherein the measurement may take place during the rotation.
In a further advantageous embodiment, the filter element includes a reflecting area. Through the measurement of the reflected intensity, it is possible to determine the amount of the deposited particles in an easy way.
In a further advantageous embodiment, the radiation source is formed so as to emit substantially monochromatic radiation. For the emitted radiation, advantageously a wavelength is chosen by which the particles to be detected in the milk behave in a significantly different way compared to the interaction of radiation in the milk, so that a clearly measurable effect ensues. Appropriately, the radiation source may emit in several selectable wavelengths.
In a further preferred embodiment, the radiation source is so arranged that during a measurement phase it transmits radiation substantially parallel to the filter surface. The detection of particles exceeding a predefined extent can, through the appropriate selection of the distance of the radiation source and the receiver from the filter surface, be achieved. For example, only particles exceeding a certain size interrupt light from laser diodes running parallel to the filter surface and, depending on the distance of the beams from the filter surface, the contact to the receiver.
In a further preferred embodiment the signal transmitter is an ultrasound transmitter. This allows the simple detection of particles directly in the milk stream, without strongly influencing the flow conditions of the milk.
Advantageously the ultrasound transmitter and the signal receiver are spatially arranged so that contact with the fluid during operation is possible. This has the effect that the transmittal and detection are not significantly impaired by the operating vacuum. Furthermore, the construction can, in a simple manner, be thereby combined in this way with the apparatus previously described for the measurement of the conductivity of the milk, in that the measurement chamber described above can be supplemented with an ultrasound transmitter and an ultrasound receiver.
In a further preferred embodiment the detection means composes an oscillating balance with a plezo element and an oscillating circuit Through this arrangement, the changes in the weight of the filter element can be very precisely determined, whereby accurate quantitative information about the amount of deposited particles can be yielded.
Further advantageous embodiments are explained in the claims as attached below.